A pseduo-hybrid of the Dubai Porta Potty and the G.I. butt wipe. A bride (or anyone in a wedding dress) is shat on, and the wedding dress then pulled up over their head, tightly, to get the worst of it off - in much the same way the tissue is used in the G.I. butt wipe. The difference from the Dubai Porta Potty, here, is that the customer is charged per weight of shit deposited, in much the same way that a Pick n Mix would be charged in a British sweet shop.
First known use was in planning conversations for a wedding, somewhere vaguely near Alicante, Spain, in 2022.
Yeah, after they did New York New York at the end of the night, they took the bride out the back for an Alicante Pick n Mix.